Extended transbasal approach: anatomy, technique, and indications.

Area of Science:

• Neurosurgery
• Anatomy

Background:

• The indications for the transbasal approach are not well-defined.
• Maximal exposure of the clivus and surrounding regions is essential for certain neurosurgical procedures.

Purpose of the Study:

• To determine the feasibility of maximal clival exposure using the transbasal approach.
• To identify key anatomical landmarks and morphometric data for safe and radical dissections.

Main Methods:

• Gross and microscopic anatomical observations were performed on 20 injected cadaveric specimens.
• Three variations of the transbasal craniotomy were compared for surgical exposure.
• Morphometric measurements were taken between key anatomical landmarks.

Main Results:

• Total ethmoidectomy and sphenoidectomy via an extended transbasal craniotomy provide maximum exposure of the ventral clivus.
• Lateral exposure limits include optic nerves, intracavernous carotid arteries, and hypoglossal canals.
• Inferior exposure is limited by the foramen magnum.

Conclusions:

• The extended transbasal approach enables maximal exposure from the suprasellar compartment to the foramen magnum.
• Morphometric data are valuable for navigating dissections, especially where bony landmarks are absent.
• Optimizing the transbasal approach requires understanding beyond initial craniotomy steps.